The present invention relates to an inkjet head provided, in printing devices, and a manufacturing method thereof. In particular, the present invention relates to a method of forming a water repellent film on the inkjet head.
In general, the inkjet head provided in printing devices such as a printer and a facsimile machine has a nozzle plate on which a plurality of nozzles for ejecting ink are arranged. In the inkjet head, the nozzles respectively communicate with pressure chambers, to which actuators such as piezoelectric elements are respectively attached. By operation of the actuator, a certain amount of ink pressurized in the pressure chamber is introduced to the nozzle, and then is ejected from the nozzle.
If the ink residues remain around an ejecting side of the nozzle, variations in an ejecting direction of the ink and/or in an ejecting amount of the ink may occur, which deteriorates accuracy of ejecting operation of the ink. For this reason, an ejecting side surface of the nozzle plate (hereafter, referred to as an ejecting surface) is typically covered with a water repellent film.
WO 99/15337 discloses an inkjet head covered with a water repellent film made of Ni-PTFE (polytetrafluoroethylene). The Ni-PTFE coating is made, for example, using electrolytic plating. The Ni-PTFE film is treated with heat at a temperature higher than the melting point of the Ni-PTFE, for example, 350° C. By the heat treatment, a portion of a surface of the Ni-PTFE film melts, by which the water repellent characteristic can be obtained.